Rhododendron plant named `Amy Cotta`

ABSTRACT

A new and distinct cultivar of Rhododendron plant named `Amy Cotta`, characterized by its compact, slow-growing, dense plants that are very freely branching; very uniform, symmetrical, rounded plant habit; dark green small leaves; uniform flowering; numerous, showy, ruffled, small lavender pink flowers; good weather-tolerance; and hardy to zone 4.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar ofevergreen Rhododendron, botanically known as Rhododendron minuscarolinianum×dauricum sempervirens and hereinafter referred to by thename `Amy Cotta`.

The new Rhododendron is a naturally-occurring mutation of theRhododendron minus caroliniarum×Dauricum sempervirens cultivar PJM (notpatented). The new Rhododendron was discovered and selected by theinventor as a single plant within a large population of plants of theparent cultivar, the Rhododendron minus carolinianum×dauricumsempervirens cultivar PJM, in a controlled environment in Portsmouth,R.I., in 1982. The selection of this plant was based on its smaller leafsize, denser growth habit and slower growth rate.

Asexual reproduction of the new Rhododendron by terminal cuttings takenin a controlled environment in Portsmouth, R.I., has shown that theunique features of this new Rhododendron are stable and reproduced trueto type in successive generations.

BRIEF SUMMARY OF THE INVENTION

The new Rhododendron has not been observed under all possibleenvironmental conditions. The phenotype may vary somewhat withvariations in environment such as temperature, daylength, lightintensity, nutrition and water status without, however, any variance ingenotype.

The following traits have been repeatedly observed and are determined tobe the unique characteristics of `Amy Cotta`. These characteristics incombination distinguish `Amy Cotta` as a new and distinct cultivar:

1. Compact, slow-growing, dense plants that are very freely branching.

2. Very uniform, symmetrical, rounded plant habit.

3. Dark green small leaves.

4. Uniform flowering.

5. Numerous, showy, ruffled, small lavender pink flowers.

6. Good weather-tolerance, hardy to zone 4.

Plants of the new Rhododendron can be compared to plants of the parentcultivar PJM. However, in side-by-side comparisons conducted inPortsmouth, R.I., plants of the new Rhododendron differ from plants ofthe cultivar PJM in the following characteristics:

1. Plants of the new Rhododendron are slower-growing and more compactthan plants of the cultivar PJM.

2. Leaves of plants of the new Rhododendron are much smaller and darkerin color than leaves of plants of the cultivar PJM.

3. Plants of the new Rhododendron are more uniform, rounded and denserthan plants of the cultivar PJM.

4. Plants of the new Rhododendron retain the lower branches and foliagebetter than plants of the cultivar PJM.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the overall appearanceof the new Rhododendron, showing the colors as true as it is reasonablypossible to obtain in colored reproductions of this type. The photographon the first sheet comprises a side perspective view of typical plant of`Amy Cotta` in full flower. The photograph on the second sheet comprisesa top perspective view of typical plants of `Amy Cotta` (left) and `PJM`(right) showing the differences in growth habit and size. Flower andfoliage colors in the photographs may appear different from the actualcolors due to light reflectance.

DETAILED BOTANICAL DESCRIPTION

The aforementioned and following observations, measurements, values, andcomparisons describe plants grown in Portsmouth, R.I., and Roanoke,Tex., under outdoor conditions which closely approximate commercialproduction conditions. Plants used for the description wereapproximately five years old.

In the following description, color references are made to The RoyalHorticultural Society Colour Chart except where general terms ofordinary dictionary significance are used.

Botanical classification: Rhododendron minus carolinianum×dauricumsempervirens `Amy Cotta`.

Parentage: Naturally-occurring mutation of Rhododendron minuscaroliniarum×dauricum sempervirens `PJM`.

Propagation:

Type.--By terminal cuttings.

Time to initiate roots.--About 25 days at temperatures of 24° C.

Time to develop roots.--About 80 days at temperatures of 24° C.

Rooting habit.--Very fine, finely-branched.

Plant description:

Plant form and growth habit.--Perennial, dense and rounded, very uniformand symmetrical plant habit. Moderate vigor. In early spring, numerousflowers per plant.

Branching habit.--Very freely branching.

Plant height, soil level to top of flowers.--About 44 cm.

Plant diameter, area of spread.--About 52 cm.

Lateral branch description.--Length: About 15 cm. Diameter: About 4 mm.Color: Gray, 197A, to brown, 173A. Texture: Immature stems, pubescent.

Foliage description:

Arrangement.--Alternate, single.

Length.--About 3.2 cm.

Width.--About 1.75 cm.

Shape.--Elliptic.

Apex.--Acute or slightly retuse.

Base.--Cuneate.

Margin.--Entire.

Texture.--Leathery, slight pubescence on midvein towards base of uppersurface of leaves.

Color.--Young foliage, upper surface: Dark green, darker than 147A.Young foliage, lower surface: Close to 147B. Mature foliage, uppersurface: Dark green, darker than 147A. Mature foliage, lower surface:147B.

Petiole.--Length: About 6 mm. Diameter: About 1 mm. Color: 144A.

Flower description:

Natural flowering season.--Spring after sufficient cool period. Earlyflowering; in the Northeast, bloom date is typically mid to late April.

Flower arrangement.--Flowers arranged at terminals in clusters of threeto four with usually about nine to twelve flowers per apex. Flowers faceupward and outward. Very freely flowering.

Flower appearance.--Single flowers. Lavender pink petals with lighterlavender to white throat. Flowers persistent. Flowers not fragrant.

Flower diameter.--About 4 cm.

Flower height.--About 2.5 cm.

Postproduction longevity.--About twelve days depending on temperatureand precipitation.

Flower bud (just starting to show petal color).--Length: About 1 cm.Diameter: About 7 mm. Shape: Ovoid.

Petals.--Appearance: Satiny. Texture: Smooth. Arrangement: Small singleflowers. Corolla consists of five fused petals. Shape: Elliptic withrounded apex. Margin: Entire with undulating edge which gives a ruffledappearance. Length: About 2.5 cm. Width: About 1.5 cm. Color: Whenopening, upper and lower surfaces: Close to 75A-75B. Fully opened, upperand lower surfaces: Close to 75A-75D. Throat: 75D to white.

Peduncles.--Length: About 1.25 cm. Angle: Upright. Strength: Flexible,strong. Color: 144A-144B.

Reproductive organs.--Androecium: Stamen number: Usually ten, whiskeredat base. Stamen length: About 2 cm. Filament color: White. Anther shape:Oblong. Anther size: About 2 mm by 1 mm. Anther color: Close to 90B,blue violet. Amount of pollen: Moderate. Pollen color: Light greenishyellow to light yellow.

Gynoecium.--Pistil length: About 2.1 cm. Stigma shape: Rounded. Stylecolor: Dark pink, close to 57C. Ovary color: Close to 139B.

Disease resistance: No known Rhododendron diseases observed to date onplants grown under commercial greenhouse conditions.

Seed production: Seed production has not been observed.

It is claimed:
 1. A new and distinct Rhododenron plant named `AmyCotta`, as illustrated and described.